65. Research-based Strategies to Minimize Stress and Improve Production Efficiency in Beef Cattle: The Maternal Bovine Appeasing Substance.

Abstract Our research group investigated the impacts of administering the maternal bovine appeasing substance (mBAS; Ferappease®, FERA Diagnostics and Biologicals; College Station, TX) on stress, health, and productivity of beef cattle across feedlot production phases and management events. Initial studies were conducted with high-risk, newly received calves (n = 120; 199 ± 1 kg) administered mBAS or mineral oil (CON) at feedlot entry and again on d 14. Calf BW gain and final BW did not differ (P ≥ 0.40), and incidence of bovine respiratory disease (BRD) was similar (P = 0.99) between treatments. A greater (P = 0.04) proportion of mBAS calves diagnosed with BRD required a single antibiotic treatment to regain health, whereas mortality was greater (P = 0.03) in CON calves. Hair cortisol concentrations were reduced (P = 0.01) on d 28, and relative abundance of Mycoplasma in nasal microbiota was decreased (P = 0.04) in mBAS calves. Pens that received mBAS had greater (P = 0.04) total liveweight gain (498 vs. 309 kg/pen) and final liveweight (2,676 vs. 2,484 kg/pen). To evaluate impacts during finishing, steers previously enrolled during the receiving period were administered mBAS or CON at the beginning of the finishing phase and at reimplanting (d 88). Feed intake did not differ (P = 0.57), whereas average daily gain and (ADG) gain:feed were greater (P ≤ 0.04) in mBAS steers, with no differences (P ≥ 0.24) detected for carcass traits. Complementing these findings, additional experiments with finishing cattle placed on feed as yearlings demonstrated consistent improvements in growth performance following mBAS administration during stressful management events. In Angus-influenced steers (n = 240), mBAS increased (P ≤ 0.04) ADG, final BW, hot carcass weight, and carcass quality traits, whereas feed intake was also greater (P ≤ 0.05), particularly following reimplanting (treatment × day; P < 0.01). In a commercial study with Bos indicus bulls (n = 2,626), mBAS increased (P ≤ 0.04) ADG, feed intake, final BW, and hot carcass weight, while reducing (P = 0.02) morbidity and mortality due to respiratory disease. To further evaluate responses to acute stress, feedlot-adapted bulls (n = 182) administered mBAS at castration had reduced (P ≤ 0.05) incidence of BRD signs and pain-related behavior, decreased (P = 0.02) hair cortisol concentrations, and improved pen-based productivity (P ≤ 0.05), whereas no treatment effects were detected (P ≥ 0.41) for growth performance. Collectively, these results demonstrate that administering mBAS to beef cattle during stressful management events reduces physiological indicators of stress and improves health outcomes, which are associated with enhanced feedlot productivity across receiving, finishing, and processing phases in both Bos taurus and Bos indicus production systems.